I. Field of the Invention
This invention relates generally to roof or ladder racks mountable on the roof of motor vehicles for transporting one or more extension ladders and/or step ladders to a work site, and more particularly to the ergonomic construction that alleviates the need for a worker to lift the ladder vertically when removing a ladder from the roof rack upon reaching a work site.
II. Discussion of the Prior Art
Work vehicles, such as commercial vans, often incorporate a roof rack adapted to support cargo of one type or another to be used at a work site. Such cargo often includes extension ladders and/or step ladders. To avoid loss of the cargo during transport and possible serious injuries to other motorists who may be traveling behind the work vehicle, various means have been devised for securing cargo and especially ladders, to the ladder rack. For example, some have used bungee cords and ropes to tie ladders in place on the vehicle-mounted roof rack, but this is generally a considerable effort, especially given the height and placement of the ladder rack on the van roof. In applicant's printed application US 2011/0214944 A1, which is hereby incorporated by reference herein, there is described a ladder rack and especially an improved clamping structure for releasably securing ladders to a roof mounted ladder rack. It comprises a pair of side rails 12 and 14 that are held in parallel spaced-apart relation by front and rear cross-bars 16 and 18. In that design, the side rails 12 and 14 are mounted so as to be upwardly offset from the top surface of the cross-bars 16 and 18.
A clamp member 60 is affixed to a shaft 42 that is journaled for rotation about an axis parallel to the rear cross-bar 18. The clamp member in the form of an L-shaped hook can be raised and lowered by manipulating a crank 82. When the clamp member 60 is in its raised position, such as shown in FIG. 1 of the aforereferenced published application, it is made to engage a ladder rung capturing the ladder between a fixed, front clamp member 22 and the rotatable clamp member 60. Because the side rails 12 and 14 are elevated with respect to the ladder-supporting cross-bars 16 and 18, a worker, standing on the ground, must reach up and lift the foot portion of the ladder over the adjacent side rail which has proven to be an arduous task for some workers, especially persons of smaller stature. The present invention obviates this problem by requiring less effort in order to transfer a ladder from its transport position atop the cross bars of the roof rack on the vehicle to a removed position. In the removed position the foot of the ladder is brought down to rest on the ground while the upper portion of the ladder remains in contact with the side rail 12 or 14 and its horn 37 or 39.
While, after-the-fact, the present invention may appear simple, it solves a practical problem of allowing a worker to more readily remove or replace ladders from and onto a van mounted roof rack without strain.